the dynamic life list does provide a way to show unobserved species (for a particular place, compared against species observed by any user in that place). for example: https://www.inaturalist.org/lifelists/animallover28?view=tree&details_view=unobservedSpecies&tree_mode=full_taxonomy&taxon_id=3&place_id=97394.
but if you want to compare against against a particular reference list of species, these days, you’ll probably have populate your own custom list of observed birds and compare your reference list against that.
or you could extract a list of species you’ve seen, extract your reference list, and compare the two lists (outside of the system). it wouldn’t be super difficult to write something that would do this. i’m probably not going to do this since lists are sort of antiquated at this point, but maybe someone else would be interested in doing this as a short coding project? (here are some relevant threads for anyone interested in going down this path: https://forum.inaturalist.org/t/easy-way-to-get-taxon-ids-for-a-list-of-300ish-taxa/41229, https://forum.inaturalist.org/t/viewing-species-in-a-project-beyond-the-top-500/11420/10, https://forum.inaturalist.org/t/create-offline-lifelist-of-your-observations/28740/6 .)